1. Field of the Invention
This invention relates to a locking coupling assembly that couples two tubular members, more particularly to an easily unlatchable cam-lock actuating device for use in a locking coupling assembly which is operable to quickly connect and disconnect two tubular members.
2. Description of the Related Art
Referring to FIG. 1, a conventional locking coupling assembly 10 disclosed in U.S. Pat. No. 5,435,604 is shown to include a cylindrical body 11 connected to a female coupling tube (not shown), a male coupling tube 12 insertable into the cylindrical body 11, two cam arms 13 pivotably mounted on the cylindrical body 11 by pivot pins 132, and a seal ring 14 mounted on an inner surface of the cylindrical body 11. Each of the cam arms 13 has a cam surface 1311 extending through a slot 114 into a bore 111 in the cylindrical body 11 for engaging the male coupling tube 12 in the bore 111 when the cam arm 13 is at a locking position. A spring-biased lock bolt 133 is movably received in a hole in each of the cam arms 13 such that a locking end 1331 extends through the hole to be inserted into a locking hole 116 in the cylindrical body 11 for retaining the cam arm 13 at the locking position. A pull ring 136 is attached to the lock bolt 133 such that, by pulling the pull ring 136, the locking end 1331 is moved to be disengaged from the locking hole 116 so as to permit turning of the respective cam arm 13 to an unlocking position. Thus, the locking coupling assembly 10 can be used to quickly connect and disconnect two tubular members, such as hoses, pipes, etc.
However, since the pull ring 136 includes a plurality of resilient loops to be hooked on the lock bolt 133, tensile deformation of the loops may occur after numerous times of use. Moreover, gripping and pulling of the pull ring 136 is uncomfortable for the user since the pull ring 136 has a relatively small surface area.